Re: Cell Propagation vs. empty & full cells
Steve,
Could not think of a formula to do what you wanted but try the attached. It has an update button which will find the latest update and copy the data back to the first sheet. If you want, the button can be taken away and have the macro run on pressing Ctrl + A or similar. Not sure what protection you will have on this but there is no error trapping built in so if you protect or hide the sheets you will get errors. These can be accomodated if you tell us what is required.
Regards,
Michael